In electrical engineering, a charging station refers to any stationary apparatus or electrical installation which serves to supply energy to mobile battery-operated devices, machines or motor vehicles by a simple placing or plugging-in operation without the energy store—for instance the traction battery of an electric car—having to be removed. Charging stations for electric cars are colloquially also referred to as “electric filling stations” and can comprise a plurality of charging points which, depending on the design, are characterized as “charging columns”.
Known here are in particular direct-current quick-charging systems (high performance charging, HPC) such as the so-called combined charging system (CCS) which is widespread in Europe. In the case of the generic direct-current charging, direct current is fed directly into the vehicle from the charging column and for this purpose provided by a high-power rectifier from the electricity network or by large buffer accumulators at solar filling stations. Within the vehicle there is situated a battery management system which communicates with the charging column in order to adjust the current intensity or to terminate the operation when a capacity limit is reached.
According to the prior art, the power electronics required for this purpose is customarily integrated in the charging column and can be loaded up to a power limit of 50 kW. Since the direct-current connections of the charging column are directly connected to corresponding connections of the traction battery, low-loss high charging currents can thus be transmitted, which allows short charging times but also results in heat generation.
In order to keep the weight and the flexibility of the charging cable low for the user, cable-cooling systems having charging cables through which a liquid flows are described in the literature. Such systems sometimes present problems upon installation, operation and maintenance. In particular, the charging cable is exposed to a high degree of wear through regular use, weathering or inappropriate handling. However, its replacement and its installation as a rule require a mounting of the components of the cooling system or a connection of the cable cooling circuit to the cooling system of the charging column. For this purpose, cooling liquid has to be filled in, on the one hand, and, in addition, the cooling circuit has to be vented for problem-free operation. These activities are time-consuming, error-prone and tie maintenance teams in situ to the charging columns.
Alternatives with leakage-free or even dead-volume-free plug connectors which could avoid a filling or venting operation are disproportionately expensive and sensitive. Thus, for instance, DE102007041110B4, which is incorporated by reference herein, discloses an electrical connection with a connection line and plug connector which each have a cavity for cooling liquid. The plug connector further has a valve which closes a first opening of the cavity if the connection point of the connection line is uncoupled from the plug connector; the connection point has a corresponding valve which closes a second opening of the cavity if the connection point is uncoupled from the plug connector.
EP800234B1, which is incorporated by reference herein, relates to a plug coupling for supply or monitoring and control lines, comprising a plug socket and plug which form three coupling points consisting of coupling pins on the one hand and coupling sleeves on the other hand, wherein, besides the coupling points for electrical lines, a coupling point for the pressure-medium line is provided and the coupling pin and the coupling sleeve of this coupling point have axial bores and terminal hose connections, and a nonreturn valve is arranged in the axial bore of the coupling sleeve and can be pressed upon by the coupling pin penetrating into the coupling sleeve.
EP2909893A1, which is incorporated by reference herein, relates to a further charging cable cooling system.